Make the meringue in 2 batches. Whisk half the egg whites until they form stiff peaks, gradually adding 240g castor sugar a little at a time until all the castor sugar is incorporated and you have a thick and glossy meringue. Fold in half the cornflour and vanilla. Spread the meringue mixture in a round motion onto a foil-lined baking sheet.

Repeat this process so you have 2 meringue nests. Place in the preheated oven and bake for 1 to 1½ hours. The meringue must be cooked but gooey inside and peel off nicely from the foil. Turn off the oven and leave the meringue to cool in the oven.
To assemble the meringue
Whip the cream until it forms stiff peaks and divide it evenly between the 2 meringue nests. Decorate each meringue layer with cherries and berries, then place one meringue on top of the other, dust with castor sugar and serve.